606 GENDER AND CHRONIC KIDNEY DISEASE IN PATIENTS WITH SPINA BIFIDA

Abstract

INTRODUCTION AND OBJECTIVES: Children born with spina bifida are at risk for chronic kidney disease (CKD). One of the goals of urologic intervention is to prevent the compromise of kidney function. Urologic intervention can include intermittent catheterization, medications, and/or lower urinary tract reconstruction. Much debate still exists regarding risk factors for developing CKD. We evaluated the role of gender on CKD in spina bifida patients. METHODS: We retrospectively evaluated spina bifida patients using the Vanderbilt Synthetic Derivative resource. The Synthetic Derivative is a collection of de-identified information extracted from the Vanderbilt University Medical Center clinical information systems. Content is changed by deletion or permutation of all identifiers contained within each record. Study inclusion criteria were: age 10 years and ICD-9 code 741 for spina bifida confirmed with specific mention of “spina bifida” or “myelomeningocele” in the patient record. Each record was then reviewed for age, sex, race, history of dialysis, history of renal transplant, serum creatinine, history of urodynamics, and history of urological operative procedures. Glomerular filtration rate (GFR) was calculated by the Modification of Diet in Renal Disease (MDRD) study equation at 18 years of age and the Bedside Schwartz equation at 18 years of age. CKD onset was defined as GFR 60, need for dialysis, or need for renal transplant. For our analysis, we assumed that patients without serum creatinine levels and without mention of CKD in the clinical record did not have CKD. Log-rank test for equality of survivor functions was used to compare the effect of gender on CKD onset. RESULTS: We identified 1196 spina bifida patients. To decrease confounding by race, we limited our analysis to the 901 patients identified as Caucasian. Of the 901 patients, 520 had documented serum creatinine values. CKD onset occurred in 54 patients (6.0%) at an average age of 34.7 years. Male spina bifida patients were more likely to develop CKD than female spina bifida patients (p 0.03). CONCLUSIONS: In our cohort of spina bifida patients, female gender was associated with less CKD onset. Whether this gender difference is due to lifestyle factors, sex hormone effects on the kidney and or lower urinary tract or a disparity in urologic and medical care remains to be elucidated.